Effects of aspirin and prostaglandin E1 on in vitro thrombolysis with urokinase. Evidence for a possible role of inhibiting platelet activity in thrombolysis

Risk factors for chemotherapy-associated liver injuries: A multivariate analysis of a group of 146 patients with colorectal metastases

BACKGROUND

Chemotherapy for colorectal liver metastases (CLM) may be associated with pathologic changes to the liver parenchyma, possibly increasing the risk of surgery. The aim of this study was to determine the risk factors for chemotherapy-associated liver injuries (CALI).

METHODS

From 1998 to 2006, 146 patients underwent a liver resection for CLM within 3 months of preoperative chemotherapy. CALI were defined as follows: steatosis > or =30%, or steatohepatitis, or moderate or severe sinusoidal lesions. Univariate and multivariate analysis were used to examine the relationship between CALI and 36 other preoperative factors.

RESULTS

Pathologic examination showed CALI in 74/146 patients (51%), including sinusoidal lesions (n = 50), steatosis > or = 30% (n = 32), and steatohepatitis (n = 15). Twenty-three patients had overlapping CALI. In multivariate analysis, BMI > 27 (P = .002), hyperglycemia > 7 mmol/l (P = .006), and an interval between chemotherapy and surgery < 4 weeks (P = .011) were independent risk factors for CALI, whereas aspirin intake was associated with reduced risk of CALI (P = .002). In multivariate analysis, synchronous metastases (P = .015), unresectable liver metastases at diagnosis (P = .034), GGT plasma level > 1.5N (P = .028), and oxaliplatin-based chemotherapy (P < .01) were risk factors for sinusoidal lesions. Aspirin intake was associated with reduced risk for sinusoidal lesions (P = .03). In multivariate analysis, BMI > 27 (P = .026) was the only risk factor for steatosis or steatohepatitis.

CONCLUSION

In patients with CLM, there are few preoperative risk factors for CALI. In patients treated by oxaliplatin-based chemotherapy, aspirin intake appears to be associated with a reduced risk of sinusoidal lesions and should be tested in a randomized phase II study.

Benefit of prostaglandin infusion in severe heart failure: preliminary clinical experience of repetitive administration

BACKGROUND

Prostaglandin E1 (PGE1) is a potent vasodilating drug, which has been used in treatment of primary pulmonary hypertension. However intravenous PGE1 infusion may be of benefit and also has been proposed as a therapeutic tool in patients with end-stage heart failure. The aim of this prospective not randomized study was to assess the clinical and instrumental effects of this agent in patients with severe heart failure and pulmonary hypertension.

METHODS

To investigate the effects of PGE1 in congestive heart failure we selected 22 consecutive patients (16 males, 6 females, mean age 63±2 years) in the mean NYHA class III, because they had pulmonary hypertension (PAPs>3 m/s and left ventricular ejection fraction (LVEF) ≤35% by echocardiography. A control group of 23 patients (19M, 4F mean age 62±5 years; 9 patients were in the NYHA class IV and 14 in the NYHA class III), with the same instrumental and clinical data, received an optimized oral treatment with beta-blockers, ACE-inhibitors, furosemide and digitalis. Right heart catheterization was performed to confirm and determine the type of pulmonary hypertension, before starting the PGE1 infusion. Clinical and echocardiography evaluation was performed during follow-up. PGE1 was infused at a mean dose of 10 ng/kg/min for a total of 24 h over three consecutive days every three months.

RESULTS

Right heart catheterization confirmed a high systolic pulmonary pressure in all patients; pre-capillary pulmonary hypertension (mean PAP>25 mm/Hg) was 25%. During a mean follow-up of 36±6 months, 16 patients died (10 in the control group and 6 in the PGE1 group). The Kaplan-Meier 3-years survival analysis was not statistically significant (Log-rank test), but at 2 months survival rates began to diverge; 36 months survival: 72.7% in the PGE1 group and 56% in the control group. The mean LVEF increased from 25.78% to 32.1% in the PGE1 group and from 23.38% to 26.15 in the control group (p<0.001); the NYHA mean class improved from 3.18 to 2.24 in the PGE1 group and from 3.46 to 3.38 in the control group (p<0.05). The PAP decreased from 57.65 to 40.82 mm/Hg (p<0.001). An AICD was implanted in 3 patients in the first group and in 5 patients in the control group. Two patients were added to the heart transplantation list.

CONCLUSION

These preliminary data suggest that intermittent PGE1 infusion in patients with advanced congestive heart failure and high pulmonary pressure is able to improve NYHA mean class (p<0.05), ventricular contractility (LVEF p<0.001), pulmonary pressure and clinical data. It hasn't been associated to morbid events or increased risk of death.

Retrospective analysis of Rt-pa thrombolysis combined with PGE1 in patients with peripheral arterial occlusions

Although thrombolysis has been established for recanalization of acute and in part chronic peripheral artery occlusions, only smaller studies exist regarding the use of long-term rt-pa infiltration-thrombolysis. The objective of this study was to evaluate the benefit of additional long-term thrombolysis in patients with peripheral arterial occlusions for whom acute thrombolysis failed. From 1992 to 1997, 323 patients with peripheral arterial occlusions were treated with rt-pa (recombinant tissue-type plasminogen activator). When the thrombolysis failed during the first 3 hours, the thrombolytic therapy was continued as a long-term treatment with 3 mg rt-pa alternated by PGE1 (2.1 mL/hr for 3 hours, concentration: 20 microg/50 mL NaCl) every 3 hours. Additional heparin was applied in doses of 15,000 IE/24 hr or more to slightly increase the partial thromboplastin time. Angiographic controls were performed every 24 hours. If necessary, a final angioplasty was performed. In 142 of the 323 patients the occlusions were recanalized during the first 3 hours; 119 patients were treated with a long-term thrombolysis and in 72 (61%) a recanalization was ultimately achieved. Thus, the recanalization rate increased to 214 of 323 patients (p < 0.02). Mean treatment time was 2.8 +/- 2.2 days, range: 1 to 13 days. The rates of recanalization were not different in iliac, femoral, or crural arteries. Fibrinogen levels did not decrease during thrombolysis. Severe bleeding (with a decrease of more than 3 g/dL hemoglobin requiring transfusion) occurred in four patients after finishing the thrombolysis with short-term and in six with long-term therapy; two required surgical treatment. The 1-, 2-, and 3-year cumulative patency rates were respectively 90.1%, 74.2% and 64.9%. Patency rates in patients with acute or long-term thrombolysis were not different. A composite thrombolytic treatment using low-dose rt-pa in combination with PGE1 offers significantly better results than an acute thrombolytic treatment alone. It can be an effective and practicable regimen in about 60% of patients in whom acute thrombolysis fails.

Prostaglandin E1 does not accelerate rTPA-induced thrombolysis in acute myocardial infarction

Fifteen patients who arrived between 6 and 24 hours after the onset of acute myocardial infarction and who were found to have totally occluded coronary arteries, received aspirin, heparin, and tissue plasminogen activator given over 3 hours. Eight patients were randomly assigned to receive intravenous prostaglandin E1, 20 ng/kg/min for 6 hours, while seven patients received placebo infusion. Coronary arteriography begun immediately before the start of tissue plasminogen activator and repeated every 15 minutes revealed restoration of antegrade flow in two of eight (25%) patients treated with prostaglandin E1 and in two of seven (28%) patients receiving placebo. Pharmacologic sampling of tissue plasminogen activator levels were performed at baseline and 30, 45, 60, 75, 90, 135, 180, 190, 210, and 240 minutes afterwards for assessment of tissue plasminogen activator antigen. There was no difference in fibrinogen levels and no difference in tissue plasminogen activator antigen levels at these time periods. Clearance values of tissue plasminogen activator were calculated and were not different between the two groups. These data do not support the use of prostaglandin E1 for the acceleration of reperfusion in patients receiving tissue plasminogen activator for acute myocardial infarction.

High dose intravenous aspirin, not low dose intravenous or oral aspirin, inhibits thrombus formation and stabilizes blood flow in experimental coronary vascular injury

OBJECTIVES

The purpose of this study was to assess the anti-thrombotic potential of various forms of aspirin administration.

BACKGROUND

Platelet activation in response to endothelial injury has been implicated in acute coronary syndromes.

METHODS

Delivering 100-microA anodal direct current to the intima of the left circumflex coronary artery in dogs at a site of moderate external stenosis provides a thrombogenic model of vascular injury. Animals were treated with aspirin (Group I, 20 mg/kg intravenously [n = 11]; Group II, 4.6 mg/kg intravenously [n = 6]; Group III, 4.6 mg/kg orally 18 h before the experiment [n = 7]) or vehicle (Group IV, control [n = 11]).

RESULTS

The time required for thrombotic occlusion to occur was longer and the incidence of thrombosis was lower in Group I (Group I, 238 +/- 7 min [n = 2]; Group II, 127 +/- 25 min [n = 3]; Group III, 156 +/- 35 min [n = 6]; Group IV, 90 +/- 11 min [n = 11]) (p < 0.05). Thrombus mass was smaller in Group I (Group I, 5.0 +/- 0.8 mg; Group II, 12.2 +/- 2.6 mg; Group III, 11.6 +/- 3.9 mg; Group IV, 9.1 +/- 1.6 mg) (p < 0.05). Initial hemodynamic variables did not differ among groups. An increase in mean arterial pressure was noted for several hours after intravenous aspirin administration in Group I (99 +/- 5 to 110 +/- 4 mm Hg) (p < 0.05). Left circumflex coronary artery blood flow was stable for 5 h in Group I (Group I, 31 +/- 2 to 26 +/- 4 ml/min) but decreased in all the other groups (Group II, 26 +/- 4 to 10 +/- 5 ml/min; Group III, 27 +/- 5 to 7 +/- 7 ml/min; Group IV, 29 +/- 4 to 0 ml/min) (p < or = 0.05). The in vivo area of left ventricle perfused by the left circumflex coronary artery was not different among groups. Platelet counts were similar and did not change over the course of the protocol. Ex vivo arachidonic acid-induced platelet aggregation decreased in all groups after aspirin (p < or = 0.001). Indium-111-labeled platelet adherence to the coronary vasculature was decreased in distal vessel segments after all doses of aspirin (p < 0.05). Platelet deposition in thrombi was similar for all treatment groups.

CONCLUSIONS

High dose intravenous aspirin has salutary effects. It stabilizes left circumflex coronary artery blood flow, prolongs the time to thrombosis, reduces the incidence of thrombotic occlusion, reduces thrombus mass and limits platelet adherence to sites of arterial injury. Low dose aspirin given intravenously or orally was ineffective. When persistent intracoronary thrombi precipitate unstable coronary syndromes, high dose intravenous aspirin may be useful in the acute period even though platelets continue to interact with injured vascular segments through aspirin-insensitive mechanisms.

Angiographic findings in a patient with primary antiphospholipid syndrome: case report

A case of antiphospholipid syndrome (APPS) is presented. A 33-year-old female presented with a right hemispheric stroke secondary to thrombosis of the middle cerebral artery. Shortly thereafter, she developed thrombosis of the right brachial artery. Despite thrombolytic therapy, progressive occlusion of this artery occurred as demonstrated by a follow-up angiogram. The patient had a history of multiple recurrent spontaneous abortions. Lupus anticoagulant, anticardiolipin antibodies, and VDRL were positive on two different occasions. The angiographic findings of multiple and progressive arterial thrombosis in young women should alert the angiographer to the possibility of APPS.

Taprostene, a stable prostacyclin analogue, enhances the thrombolytic efficacy of saruplase (recombinant single-chain urokinase-type plasminogen activator) in rabbits with pulmonary embolized thrombi

Cooperative effects of the prostacyclin analogue taprostene and the thrombolytic agent saruplase (r-scu-PA) were studied in anesthetized rabbits with pulmonary thromboembolism. Thrombolysis was evaluated as decrease of the total weight and of the incorporated 125J-fibrin-radioactivity of the embolized thrombi. Saruplase (10.0-46.4 micrograms/kg.min, i.v.) produced dose-dependent lytic effects. Taprostene, infused in a dose (0.1 microgram/kg.min, i.v.) that inhibited ADP-induced decrease of circulating platelets by 56%, reduced the total thrombus weight (p less than 0.05 vs control) and in combination it further augmented the saruplase (21.5 micrograms/kg.min)-induced thrombolysis (p less than 0.05 vs saruplase alone). Taprostene did not increase the spontaneous lysis rate of the incorporated 125J-fibrin (7.3 +/- 1.4% vs 8.1 +/- 1.4%), but further enhanced the fibrinolytic effect of saruplase (37.2 +/- 5.6% saruplase vs 53.6 +/- 2.3% saruplase + taprostene; p less than 0.05). This overadditive synergism is tentatively ascribed to the platelet inhibition by the prostacyclin analogue that may facilitate the action of the thrombolytic agent. Taprostene lowered mean arterial blood pressure by 22% in anesthetized rabbits; it did not significantly modify the slight decrease of the plasma fibrinogen level (20-30%) by 21.5 micrograms/kg.min saruplase. The results show that the prostacyclin analogue taprostene reduces the total thrombus weight and enhances the efficacy of the thrombolytic agent saruplase in pulmonary thromboembolism in rabbits.

Unstable angina or non-Q wave infarction despite long-term aspirin: response to thrombolytic therapy with implications on mechanisms

The pathophysiology and optimal therapy of patients who develop unstable angina in spite of long-term aspirin intake ("aspirin failure") have not been well defined. As part of a prospective study of thrombolytic therapy, 19 consecutive patients were identified who were admitted with unstable angina despite long-term aspirin therapy, and they were compared with 12 patients with unstable angina without previous aspirin use. Both groups received urokinase (3.0 million units over 30 minutes intravenously), maximal antianginal therapy, and intravenous heparin. Fibrinolytic system effects were characterized with serial measurements of fibrinogen, d-dimer, and fibrinogen degradation products (FDPs) at baseline and over the 24 hours following therapy. In comparison with those without previous aspirin use, the aspirin failure patients demonstrated greater d-dimer production after treatment at all points, the values becoming highly significant at 24 hours (1337 +/- 671 versus 709 +/- 620 ng/dl, p less than 0.02), as well as significantly greater FDPs at all points in the first 24 hours after treatment. Post-treatment arteriography (at 24 to 72 hours) indicated more extensive coronary artery disease in the aspirin failure patients (2.56 +/- 8.3 versus 1.63 +/- 1.06 vessels with greater than 50% stenosis, p less than 0.01) and more severe stenoses of the culprit artery (92.7 +/- 22.9% versus 77.3 +/- 36.9% diameter reduction, p = 0.09). By 7 days, both groups had equally low rates of new ischemic events or infarction (3 of 12 for no aspirin versus 4 of 19 for aspirin failure patients). Despite more extensive underlying coronary disease, unstable angina after long-term aspirin therapy appears to respond equally well to thrombolytic therapy.(ABSTRACT TRUNCATED AT 250 WORDS)